GAIA Level 1 Morbidly Adherent Placentation

**Semantic type:** Classification

**Definition:** GAIA Level 1 Morbidly Adherent Placentation is defined by three criteria: first, evidence of placenta previa by either a second- or third-trimester ultrasound or an MRI; second, one of the following ultrasound features must be present: for Greyscale: a) Loss of the retroplacental sonolucent zone; OR b) Irregular retroplacental sonolucent zone; OR c) Thinning or disruption of the hyperechoic serosa-bladder interface; OR d) Presence of focal exophytic masses invading the urinary bladder; OR e) Abnormal placental lacunae; for Color Doppler: a) Diffuse or focal lacunar flow; OR b) Vascular lakes with turbulent flow (peak systolic velocity over 15 cm/s); OR c) Hypervascularity of serosa-bladder interface; OR d) Markedly dilated vessels over peripheral subplacental zone; for 3D Power Doppler: a) Numerous coherent vessels involving the entire uterine serosa-bladder junction (basal view); OR b) Hypervascularity (lateral view); OR c) Inseparable cotyledonal and intervillous circulations, chaotic branching, and detour vessels (lateral view); third, one of the following risk factors must be present: a) Prior cesarean delivery; OR b) Prior uterine surgery (including endometrial ablation); OR c) Cesarean scar pregnancy. Alternatively, Level 1 may be defined as morbidly adherent placentation found on histology in a hysterectomy or partial wedge resection specimen.

**Synonyms:** - Global Alignment of Immunization safety Assessment in pregnancy Level 1 Morbidly Adherent Placentation - Level 1 Morbidly Adherent Placentation